ETONITAZENE ENHANCED COCAINE SELF-ADMINISTRATION IS NOT BLOCKED BY NALOXONAZINE

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。许多多种药物滥用者自行使用可卡因和海洛因的组合，通常被称为速球。海洛因被认为是通过阿片受体机制增强可卡因的行为效应。为了进一步评估mu受体在阿片类药物诱导的可卡因行为效应增强中的作用，本子项目研究了一种被认为有效的mu-1受体激动剂——依托硝泽尼对可卡因自我给药的调节。当与可卡因联合使用时，不维持自我给药的依替硝嗪剂量导致可卡因剂量-反应曲线向左移动。假定的mu-1受体拮抗剂纳洛唑嗪预处理在自我给药前1小时或24小时给药时，不会减弱依托硝嗪诱导的可卡因自我给药增强。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Many polydrug abusers self-administer combinations of cocaine and heroin, commonly known as a speedball. Heroin is thought to enhance the behavioral effects of cocaine through a mu opioid receptor mechanism. To further evaluate the role of mu receptors in opioid-induced enhancement of the behavioral effects of cocaine, this subproject investigated the modulation of cocaine self-administration by etonitazene, a potent putative mu-1 receptor agonist. When combined with cocaine, doses of etonitazene that did not maintain self-administration resulted in a leftward shift in the cocaine dose-response curve. Pretreatment with the putative mu-1 receptor antagonist naloxonazine did not attenuate etonitazene-induced enhancement of cocaine self-administration when administered at 1 h or 24 h prior to the self-administration session.